"The terrifying thing was, I couldn't get up," she recalls.

At 135kg, it took Libby 10 minutes to roll onto her side and then onto her knees before slowly making her way to her feet. The pressure on her knees and feet was enormous.

It shocked Libby, an executive assistant at the Treasury, so much that she made an appointment to investigate bariatric surgery options that very same week. She'd been Googling a vertical sleeve gastrectomy - known colloquially as a "gastric sleeve" - for months but the terror of her fall made her finally commit to having the operation.

"It was such a wake up call," she says.

"I just thought, I could have done this on a road and been run over by a car - or fallen down a cliff - and this isn't the life I want.

"I was desperate."

The former personal trainer, who can pinpoint the exact stage of her life she began overeating - "I married a man who was an alcoholic and over time to cope with his alcoholism, I ate" - booked in for a gastric sleeve operation in June of 2015.

The surgery was performed by Canberra bariatric surgeon Dr Charles Mosse.

The objective of gastric sleeve surgery is to significantly reduce the capacity of the stomach, and therefore the level of ghrelin, or "hunger hormone" being produced.

During the two-hour operation, 85 per cent of the stomach is removed, leaving a long thin passage "or sleeve" for food to be processed in. According to Dr Mosse, about 200 Canberrans undergo gastric sleeve surgery each year.

A recent Canberra Times story featuring Queanbeyan gastric sleeve patient Kate Gibbs angered Libby.

She's "tired of seeing these stories all over the media which show people in the first 12 months of their weight loss journey", she says, and wants to describe what her life is like, three years after having her stomach reduced so significantly.

"The only way you are ever going to lose all the weight with this procedure is to be prepared," she says.

"This is not a quick fix.

"I just want people to know what I wish I'd known back when considering the operation."

Like the fact your new longer, thinner stomach can stretch.

One year post-surgery, Libby could eat half a sandwich for lunch. By the end of the second year, it was an entire sandwich. By two years and six months, the ghrelin was back and Libby was hungry again. She craved sugar and fat as much as she had prior to surgery.

"I believed, from all the literature I'd read, that if I had this [operation] done I would never, ever be able to overeat again," she says.

"And I think a lot of people believe that.

"In my mind I thought if I do this, I won't have to worry again - even though I knew that over time [the stomach] stretched marginally, I never expected this."

Libby also wants Canberrans considering gastric sleeve surgery to be prepared for the fact they may actually put weight back on after the initial massive weight loss.

"All up I lost 55 kilos but I got the shock of my life six months ago when I stood on the scales and had put on eight kilos," she says. "I was depressed for the rest of the week."

According to Ms Oakes-Ash's bariatric surgeon, Dr Charles Mosse, the important thing for potential patients to understand is that gastric sleeve surgery "is not weight loss surgery".

"Both bariatric and metabolic surgeries are surgeries for blunt signals that are the drivers for obesity - which then makes it easier for patients to change behaviour," Dr Mosse says.

"People think they're coming in for an operation but the outcome we really want for them is behaviour change - the operation is simply the mechanism to do that."

According to Dr Mosse, weight gain after bariatric surgery is "inevitable".

"If we refer to the Swedish Obese Subjects Trial, the weight loss curve over 30 years of the trial shows that everybody who's had surgery - whether that's a gastric band, a sleeve, a bypass, BPD or a switch - will inevitably lose weight, plateau for a while and then at some point they will gain some weight.

"So [Ms Oakes-Ash] is quite right, if patients overeat - or inevitably maybe the sleeve will stretch anyway - patients will then become more hungry.

"Those patients that are able to maintain their weight loss are the ones that are able to maintain the behaviour change."

While the side effects of Libby's surgery have included hair loss, excess skin, and the diarrhoea-like "dumping syndrome", she mostly wants people considering the operation to work just as hard on their mental health as their physical health.

"I had a couple of traumas in my life that really deeply affected me and because food is an addiction, I didn't drink or take drugs, I ate," she says.

"If you're considering the surgery, please go with a surgeon who offers excellent psychological support and look into working with a counsellor or psychologist after surgery.

"Do I regret having the operation? No. But three years on I'm working just as hard as I ever have to lose weight and mentally manage my addiction to food."